We've been hanging out for over a year and I honestly don't really remember my first impression of this person (S), or our first conversations...but the more we hang out and interact, the more I notice how similar our personalities are. We're both sarcastic to the point of other people calling us mean. We both have anger tendencies we try to avoid. We often respond with the exact same words, sometimes at the same time. It's gotten to the point where sometimes, it's just bizarre.

At first, I didn't have a problem. As we spent more time together, our personalities came out and we became friends. Then I developed a stupid, pointless crush.

It's stupid because sometimes S is so cynical that I try to step back and ask myself if I view the world with that much negativity.
It's pointless because I'm married. This has been the hardest and worst 6 months of marriage in our 5+ years due to my partner's job. I honestly don't know if I'll be married in a few months- BUT if I end up divorced, I have no desire to marry S (we have different life goals, I think).

The more real the possibility of divorce is in my life, the more I fantasize about S confessing some attraction to me.
It's dumb, and I don't believe S finds me attractive.
Here's hoping my feelings fade and my friendship with S continues to flourish.

Sounds like you have an infatuation with this coworker. I agree that you should definitely do what makes you happy but look close at what that is. Would you really be happy being with someone that is so much like yourself? Or would that get old? Think about the reasons you married your spouse to begin with. Is this just a rut you're willing to work through or are you genuinely not happy with him/her? Time will tell. I hope you figure it out.